1. Field of the Invention
The present invention is directed to a system for recording color transformations made to a reference image and creating a transformation to be applied to subsequent images from the recording and, more particularly, to a system in which a color change recording tracer representing the domain of colors of a designated color space is attached and made integral with an image, the image, including the tracer, undergoes color changes controlled by a user which consequently changes the tracer and the color changes recorded by the tracer are used to create a transformation that is used to transform other images.
2. Description of the Related Art
Today it is often the case that an operator of a color processing system will want to make color changes or "edits" in a color space or coordinate system, such as LAB, to a reference color image and then use those reference color image changes to guide the changes to a large collection of other similar images also in that same color space (LAB).
The prior art allows the operator to do this by making the changes and recording the changes as a script of operator key strokes, etc. The script, which is separate and apart from the image that has been changed, is then used to guide the same operations on other images. In this method the operator can see the effect of the changes on the reference image, however, the changes are recorded in a way that makes it difficult to perform such changes on a large number of images since completely executing all the keystrokes, etc. of the operator for every image that needs to be changed is very time consuming.
The prior art also allows color edits to be made in the transformation that changes color values from one color space to another, such as from LAB to RGB. In this space-to-space conversion the operator is presented with a color domain table in visual form in the source color space, which is converted to the destination space through a given translation method, and which is presented visually as it would appear in the destination color space. The translation method is recorded in the table and is used to govern the conversion of other images into the destination color space, for example to convert color values in LAB to color values in the RGB space. In this method the user has no reference image on which to view the color edits and the changes do not reflect any changes that the operator wants to make to the image while it is in the target color space.
Another method of calibrating between color devices is described in U.S. Pat. No. 5,339,176. In this method a digital color image, which can be a group of color blocks or an image of a scene, is digitally converted from one space into another space and the two color images are compared to determine the error between the images. The comparison is performed by measuring the color differences between analog versions of images using a color reading device, such as a reference colorimetric scanner. The error is used to construct a corrected transform that will allow accurate reproduction in the second color space. Once again this method leaves the operator with no way of recording the in-space color edits that the operator may want to make to the image in either the first or second spaces before or after the space-to-space transformation.
Because of the complexity of learning and using color processing packages, the operators of color processing systems want to be able to rely on using color processing packages with which they are familiar. As a result, even if a package has new and very useful features operators tend to use the older packages because of familiarity.
What is needed is a method that allows an operator to see the effect of the color edits, records them along with the changes made in the image and records them in a format that allows easy creation of color transformations for other images while allowing the operator to use a package to make the changes with which the operator is familiar.